The EV Battery Management System (BMS) with Charger Monitor and Fire Protection along with Active Cell Balancing is developed to improve the safety, efficiency, and lifespan of electric vehicle battery packs. The system continuously monitors key parameters such as individual cell voltages, temperature, State of Charge (SOC), and State of Health (SOH). A PIC microcontroller acts as the central control unit, acquiring real-time data from voltage sensors and an LM35 temperature sensor through its ADC. Based on SOC and SOH calculations derived from voltage measurements, the microcontroller controls relay operations to regulate battery charging, where the relay functions as a switch to turn the charging connection ON or OFF. The system incorporates an active cell balancing technique using relay-based switching between battery cells (1–2, 2–3, and 1–3). This method transfers charge from higher-voltage cells to lower-voltage cells, ensuring uniform voltage distribution across the battery pack and preventing overcharging or deep discharging. The charger monitoring section supervises the regulated power supply and charging circuit to maintain controlled current and voltage delivery, thereby improving charging efficiency and protecting the battery from electrical stress. For enhanced safety, fire protection mechanisms are implemented through continuous temperature monitoring. If abnormal temperature rise or over-voltage conditions are detected, the system activates protective measures such as triggering a buzzer alarm, switching on a cooling fan, isolating faulty cells using relays, and displaying warnings on the LCD module. Additionally, the ESP8266 Wi-Fi module enables IoT-based remote monitoring by transmitting real-time voltage, temperature, SOC, SOH and activate cell balancing data to the ThingSpeak cloud platform, while the LCD provides local status display. The overall system ensures reliable battery performance, prevents thermal runaway, and supports intelligent energy management in electric vehicles.      

Objectives:

• To develop an EV Battery Management System (BMS) for safe and efficient battery operation.
• To monitor battery voltage, temperature, State of Charge (SOC), and State of Health (SOH).
• To implement active cell balancing for equal voltage distribution among battery cells.
• To monitor and control the battery charging process.
• To provide fire protection by detecting overheating and activating safety measures.
• To display battery status on an LCD and upload data to the ThingSpeak cloud using IoT.
• To improve battery safety, performance, and lifespan.

      The major building blocks of this project are:

• Regulated power supply
• PIC Microcontroller.
• Temperature sensor.
• Voltage sensor.
• Buzzer.
• Three battery packs
• Six Relays.
• Charging Circuit.
• LCD display.
• LED Indicators
• Crystal oscillator
• Reset button.
• ESP8266 Wi-Fi module.
• Load(LEDs).
• Cooling fan.

        Software’s used:

• PIC-C compiler for Embedded C programming.
• PIC kit 2 programmer for dumping code into Micro controller.
• Express SCH for Circuit design.

     

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